The present invention relates to an automatic apparatus for constructing frame structures from standard raw materials, and particularly to apparatus for constructing building stud walls.
In the building construction industry the construction of building stud walls, that is, the "framing" of a building, is typically a highly labor intensive activity and is thus very expensive. Such walls are conventionally made by assembling a plurality of elongate wooden studs vertically in parallel relation to one another at predetermined intervals longitudinally between and perpendicular to a pair of elongate horizontally-disposed wooden plate members, and nailing the studs to the plates. The frame thus assembled and nailed together, if for an outside wall, is then covered on at least one side by sheathing, usually plywood sheets which are nailed to the frame. Ordinarily, the apertures for doors, windows and the like are formed by precutting the parts of the wall prior to assembly, and holes for the electrical and plumbing conduit are drilled by the appropriate subcontractor after the entire building frame is constructed and sheathed. All of these steps ordinarily require the efforts of a number of individual laborers at the building site and are performed at different times. However, it has been found that the expense of framing can be considerably reduced by applying mass production techniques to produce prefabricated walls which may be erected at the building site in partially finished form, and that the cost can be further reduced and the quality increased by use of automatic machinery to produce the walls.
Several apparatus have previously been invented which attempt to accomplish effectively the result of automatically, or semi-automatically, manufacturing prefabricated wall frames. For example, Hurn et al. U.S. Pat. No. 3,564,702 discloses a type of apparatus for assembling part of a wall frame, but is quite complex and does not show any specific mechanism for feeding those parts to the assembly apparatus or for completing the wall by adding sheathing and cutting holes for windows, doors or conduit. Kellner et al U.S. Pat. No. 3,851,384 also shows an apparatus for manufacturing a prefabricated building wall, but is even more complex, requiring a very complicated mechanicam for assembling the parts of the wall. Similarly, Bamford, Sr., U.S. Pat. No. 2,574,163 discloses an apparatus for assembling a building wall, but it utilizes complex moving mechanism for distributing the parts of a wall over an assembly table and requires that some of those parts be individually prefabricated. Jureit et al. U.S. Pat. No. 3,685,129 and Carroll U.S. Pat. No. 3,399,445 also disclose apparatus of this general type.
Despite the aforementioned inventions disclosed in previous patents for constructing building walls, there remains a need for an improved and more efficient apparatus for constructing such walls which minimizes human labor, produces with a high degree of accuracy and speed a prefabricated sheathed wall having apertures for doors, windows and the like formed therein, and is uncomplicated yet flexible in its application.